Onshore oil and gas sector guidance

13. Monitoring emissions for onshore oil and gas activities

Developing a monitoring programme, baseline monitoring and site condition reports for onshore oil and gas activities.

13.1 Developing a monitoring programme

Once you have your permit, you must monitor your emissions and the surrounding environment to show that your:

  • activities are not harming the environment
  • emissions are within any limits specified in your permit

The guide Control and monitor emissions for your environmental permits has general information about controlling and monitoring emissions.

The starting point for developing a monitoring programme is to:

  • develop a detailed conceptual model of your site - including the main sources, pathways and receptors
  • carry out the necessary risk assessments – based on activities on your site

The guide Risk assessments for your environmental permit explains the source, pathway, receptor model and which risk assessments you may need to carry out.

Your conceptual model should recognise that your operations will vary over time and this may affect the:

  • links between the main sources, pathways and receptors
  • risks from your activities

As a result, your choice of monitoring techniques and frequencies needs to reflect any changes during the lifecycle of an oil and gas development.

As a minimum, your monitoring should include:

  • baseline monitoring – before you start operations
  • monitoring through the operational lifecycle of a site
  • decommissioning and post-abandonment monitoring before you apply to surrender a permit

Your permit conditions will specify exactly what monitoring you need to do. These conditions will be based on the assessed level of risk from your proposed activities.

Monitoring standards

The person who carries out your monitoring must be competent and work to the recognised standards such as the Environment Agency’s monitoring certification scheme (MCERTS).

MCERTS sets the monitoring standards businesses should meet. The Environment Agency recommends that you use the MCERTS scheme where applicable. You can use another certified monitoring standard but you must provide evidence that it is equivalent to the MCERTS standards.

There are no prescriptive BAT requirements for how to carry out monitoring. Monitoring methods need to be flexible to meet specific site or operational conditions.

You must use a laboratory accredited by the United Kingdom Accreditation Service to carry out analysis for your monitoring.

13.2 Baseline monitoring and site condition report

You need to carry out some monitoring before starting your operations so you can set a baseline. This is the baseline against which the state of the land and groundwater will be compared in future.

You must include this baseline information in a site condition report (SCR). A SCR describes the condition of the land and groundwater at the site before your operations start. In some circumstances it also describes local air quality. You must produce a SCR for every permit you apply for.

You should use the H5 Site Condition Report guidance and template to help you produce your SCR.

If you plan to operate a flare, engine or generator or vent emissions to air, the Environment Agency may ask you to include an assessment of local air quality in your SCR.

If you are granted an environmental permit, you will need to update your SCR throughout the life of your permit. You must record information about activities that could affect the condition of the land and groundwater at your site. This would include information about:

  • drilling activities
  • hydraulic fracturing and other well stimulation activities
  • acid washing
  • surface spillages
  • leaks from the well shaft
  • seismic events
  • failure of secondary or tertiary containment
  • any site remediation activities you carry out
  • results of any borehole monitoring you carry out
  • any periods of suspension for the well
  • well capping and abandonment
  • flaring of waste gases
  • fugitive or other emissions

When you want to decommission a site and before you apply to surrender your permit, you must return the site to a satisfactory state.

You must produce a surrender SCR to accompany your application to surrender your permit. This report must show that the condition of land and groundwater on your site has not deteriorated significantly when compared to the baseline SCR.

The Environment Agency may refuse your application to surrender your permit if they think that:

  • the land or groundwater are not in a satisfactory state
  • there is an ongoing risk to the environment

If this happens, you may have to carry out more site remediation or post-decommissioning monitoring, or both.

13.3 Waste monitoring

For extractive wastes the Environment Agency expects you to monitor the quantity and composition of:

  • produced waters and flowback fluids produced - and quantities sent off-site for disposal
  • any waste gas or vapours
  • waste drilling muds and drill cuttings produced

When monitoring the quantity and composition of wastes it is important that you also record the source of the waste.

You must sample each consignment of waste flowback fluid before you send it off-site for disposal. You must keep a reference sample for further independent analysis.

If your extractive wastes are radioactive, you will need to also carry out radioactive substances monitoring.

13.4 Radioactive substances monitoring

You must analyse and monitor aqueous and solid radioactive waste.

For onshore oil and gas operations, the Environment Agency has set limits and monitoring requirements in line with the off-shore environment and emissions monitoring system.

Aqueous radioactive waste

For aqueous radioactive waste, you must take at least one representative sample of each waste form disposed of and analyse for:

  • Ra-226
  • Ra-228 (which may be inferred via Ac-228 measurement)
  • Pb-210
  • Po-210

For each separate disposal route you must calculate the total:

  • volume of waste disposed of each month in cubic metres
  • amount of activity for each radionuclide in becquerels (Bq/l) per month

For aqueous waste injected into underground strata, calculate the concentration Bq/l of each radionuclide on a rolling 12 monthly average.

Your total disposals must include off-site transfer and the re-injection of produced water, but not NORM contaminated well stimulation fluid remaining in situ.

Wherever practicable, you should not remove the aqueous waste from site, or dispose of it on site, until the results of your measurements and analysis are available.

Solid radioactive waste

For solid radioactive waste, you must take at least one representative sample from each waste form disposed of and analyse for:

  • Ra 226
  • Ra 228
  • Th 228
  • Pb 210
  • Po 210

For each consignment of solid radioactive waste removed from the site, you must calculate the total:

  • volume of the waste disposed of each month in cubic metres
  • amount of activity for each radionuclide in Bq/l per month

You must obtain the results of analyses before removing radioactive waste from the site.

13.5 Air emissions monitoring

You may need to monitor emissions to air of these substances:

  • combustion products
  • non-combusted methane from waste gas flares, gas engines or micro turbines
  • fugitive methane or volatile organic compound emissions from infrastructure leaks and storage tanks
  • emissions from crude oil storage tank vents or crude oil transfers

If you are carrying out hydraulic fracturing you will need to apply to BEIS for a hydraulic fracturing consent. To obtain this consent, you need to monitor methane emissions to air. If you’re already doing this for your environmental permit, you can use your methane monitoring strategy to demonstrate to BEIS that you are meeting this requirement.

Ambient air monitoring

You may need to carry out ambient air monitoring to show that the air emissions from your site are not causing pollution. The Environment Agency may ask you to do this if:

  • monitoring shows that emissions from your site are higher than those predicted in your permit application
  • the site is in an air quality management area

You may also choose to carry out ambient air monitoring to provide reassurance to local communities that your activities are not having a detrimental effect on local air quality.

If you need to carry out ambient air monitoring you should refer to M8 monitoring ambient air technical guidance note.

If you are carrying out hydraulic fracturing, you will need to produce a methane monitoring strategy for agreement by the Environment Agency. This will be part of the emissions monitoring plan. You must implement this strategy to establish:

  • baseline levels of methane
  • methane levels during operations on site

When developing your strategy you should consider the:

  • duration and variety of operations
  • sampling period
  • turnaround time of results
  • site leak detection and repair plan you will put in place

The Environment Agency has produced a leak detection and repair protocol which operators can use to help develop their plans. Contact your local Environment Agency office if you would like to see a copy.

You should read M8 monitoring ambient air technical guidance note when you develop your strategy.

13.6 Noise monitoring

Mining waste and installation permits include a noise management condition. You may need to produce and implement a noise management plan. As part of this plan, you may be asked to survey potential sources of noise including:

  • pumps
  • diesel generators
  • pneumatic controllers
  • flares, engines and vents
  • gas leaks

Read H3 part 2 noise assessment and control for more information.

13.7 Groundwater monitoring

You will need to carry out groundwater monitoring (requisite surveillance) if you have a permit to carry out a groundwater activity.

You determine your groundwater monitoring by developing a conceptual model of the site that:

  • sets out the hydrogeological regime
  • identifies all groundwater bearing units
  • identifies any interdependent water features

The guide Groundwater risk assessment for your environmental permit has more information about developing a conceptual model and doing a hydrogeological risk assessment.

You need to monitor groundwater in areas where your activities could result in:

  • a decline in groundwater quality
  • a detrimental impact on sensitive receptors
  • contravention of Water Framework Directive objectives – especially those preventing the deterioration of surface water or groundwater bodies

The only situation in which you do not need to monitor groundwater is if a hydrogeological risk assessment shows there are no groundwater (or groundwater dependent) receptors close by which could be affected by your activities.

Monitoring boreholes

You must talk to the Environment Agency before installing any monitoring boreholes. You must install and operate these in a way that does not pollute groundwater or compromise your site containment measures.

The number and location of your monitoring boreholes will depend on the characteristics of the site. You will need to install the number of boreholes needed to identify:

  • the direction of groundwater flow across the site - consider any potential receptors
  • any off site potential pollution sources – work out if changes in groundwater quality are caused by activities on your site or by other influences off site

You may need to install groundwater monitoring points outside the site boundary.

You may also need to monitor:

  • other groundwater dependent water features, such as springs and wetlands
  • off-site monitoring points owned by third parties

The document Guidance on the design and installation of groundwater quality monitoring points provides further information.

Substances to monitor

The hydrogeological conditions and the activities you are carrying out on your site will determine the substances you need to monitor.

When monitoring, you should analyse the groundwater samples for any chemicals you are likely to use on site during the life of your permit. Depending on your operations, you may also need to monitor likely constituents of flowback fluid or basic sewage parameters if you are discharging sewage effluent.

The main substances of concern are likely to be:

  • methane
  • hydrocarbons
  • salinity
  • metals
  • ammonia

When working out the range of parameters to monitor, you should:

  • refer to the groundwater risk assessment carried out for your permit application
  • consider known local groundwater sensitivities
  • talk to the Environment Agency

If you will be carrying out hydraulic fracturing, you will need to monitor the level of methane in groundwater for 12 months before the hydraulic fracturing begins. You will need to demonstrate to BEIS that you have done this in order to obtain your hydraulic fracturing consent. You can include this information in the groundwater monitoring plan you send to the Environment Agency with your environmental permit application.

Monitoring frequency

How often you need to take monitoring samples will depend on the hydrogeological conditions and the activities you will carry out on site. You may need to sample less often in areas where there is a good understanding of groundwater quality. In locations where there is limited existing data, you will need to sample more often.

The minimum baseline data set will be at least 3 samples per sampling point taken over a 3 month period. This will allow you to observe natural variations. You must do this before any drilling takes place, and if possible, before constructing a new site. You will need to take more samples when you need to identify seasonal variations.

Your monitoring frequency will be set out in your permit once your site becomes operational.

Groundwater monitoring at decommissioned sites

Generally, you will need to continue groundwater monitoring based on your site specific risk assessment until the Environment Agency is satisfied that there is no ongoing risk to the environment.

13.8 Surface water monitoring

If you have a permit to discharge to surface water you may need to monitor the discharge. You must take samples and analyse them before you discharge.

To decide what techniques you should use to sample and analyse your releases to surface water you should read M18 monitoring of discharges to water and sewer guidance.

When positioning surface water monitoring locations, you should locate at least one upstream of the site, and at least one downstream. This will allow you to compare water quality coming into and out of the site.

It is important that external influences do not affect the surface water samples you are collecting. Avoid collecting samples close to banks or beds as this can disturb the water column. You should carefully select the locations so that the act of sampling does not affect the result, for example by:

  • mixing the water column
  • artificially creating turbidity
  • aeration during filling
  • contaminating the sample with algae

13.9 Water abstraction monitoring

Your abstraction licence will set out the conditions for your abstraction. These will include when, where, how much, and for what purpose you can abstract water.

You must measure how much water you abstract and send this information to the Environment Agency. Read Manage your water abstraction or impoundment licence for more information.